Objectives: a) To further understand the interaction between the gabergic and dopaminergic pathways, the effects of DA receptor blocking agents and receptor agonists and lesions of the nigro-striatal DA pathway will be studied on GABA turnover. Glutamatedecarboxylase will also be studied in the schizophrenic brain especially in the DA cell- body and terminal rich regions and compared with controls to see if there is in fact a degeneration of GABA pathways in the schizophrenic brain. b) Analize the effect of morphine and morphine-like drugs on central adrenaline and dopamine pathways and try and relate these effects to their pharmacological properties especially their analgesic actions. c) To study the actions of antidepressant drugs on the uptake of adrenaline into the adrenaline nerve terminals. d) Further experiments will be performed to evaluate the hypothesis that the benzodiazepines may act mainly by releasing GABA and in this way exert their pharmacological effects and their actions on CA pathways.